On Fri 26-08-16 13:47:47, Andi Kleen wrote: > Christoph Lameter <cl@xxxxxxxxx> writes: > > > >> If you want to rework the VM to use a larger fundamental unit, track > >> sub-units where required and deal with the internal fragmentation issues > >> then by all means go ahead and deal with it. > > > > Hmmm... The time problem is always there. Tried various approaches over > > the last decade. Could be a massive project. We really would need a > > larger group of developers to effectively do this. > > I'm surprised that compactions is not able to fix the fragmentation. > Is the problem that there are too many non movable objects around? Compaction can certainly help and the more we are proactive in that direction the better. Vlastimil has already done a first step in that direction and we a have a dedicated kcompactd kernel thread for that purpose. But I guess what Mel had in mind is the latency of higher order pages which is inherently higher with the current page allocator no matter how well the compaction works. There are other changes, mostly for the fast path, needed to make higher order pages less of a second citizen. -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>